36 research outputs found
Characterization of the magnesium alloy AZ31 surface in the ionic liquid trihexyl(tetradecyl)phosphonium bis(trifluoromethanesulfonyl)amide
Evaluation of X-ray/EUV Nanolithography Facility at AS Through Wavefront Propagation Simulations
Synchrotron light sources can provide the required spatial coherence,
stability and control that is required to support the development of advanced
lithography at the extreme ultraviolet and soft X-ray wavelengths that are
relevant to current and future fabricating technologies. Here we present an
evaluation of the optical performance of the soft X-ray (SXR) beamline of the
Australian Synchrotron (AS) and its suitability for developing interference
lithography using radiation in the 91.8 eV (13.5 nm) to 300 eV (4.13 nm) range.
A comprehensive physical optics model of the APPLE-II undulator source and SXR
beamline was constructed to simulate the properties of the illumination at the
proposed location of a photomask, as a function of photon energy, collimation,
and monochromator parameters. The model is validated using a combination of
experimental measurements of the photon intensity distribution of the undulator
harmonics. We show that the undulator harmonics intensity ratio can be
accurately measured using an imaging detector and controlled using beamline
optics. Finally, we evaluate photomask geometric constraints and achievable
performance for the limiting case of fully spatially coherent illumination.Comment: 21 pages, 7 figures, 3 tables. Preprint: submitted to Journal of
Synchrotron Radiation 16/11/2
The influence of noise on image quality in phase-diverse coherent diffraction imaging
Phase-diverse coherent diffraction imaging provides a route to high sensitivity and resolution with low radiation dose. To take full advantage of this, the characteristics and tolerable limits of measurement noise for high quality images must be understood. In this work we show the artefacts that manifest in images recovered from simulated data with noise of various characteristics in the illumination and diffraction pattern. We explore the limits at which images of acceptable quality can be obtained and suggest qualitative guidelines that would allow for faster data acquisition and minimize radiation dose
Application of a complex constraint for biological samples in coherent diffractive imaging
Free access on publisher website We demonstrate the application of a complex constraint in the reconstruction of images from phase-diverse Fresnel coherent diffraction data for heterogeneous biological objects. The application of this constraint is shown to improve the quality of the reconstruction of both the phase and the magnitude of the complex object transmission function
Synchrotron multi-modal, multi-scale chemical and structural imaging of vein-bearing shales
The coupling between fluid transport, chemical reactions, and deformation constitutes one of the frontiers of geoscientific research. From an analytical perspective, a fundamental challenge is posed by the fact that sub-nanometre- to micrometre-scale structures play a vital role in the macroscopic (centimetre- to metre-scale) response of deforming, reacting, fluid-bearing rocks. Sample analysis with conventional laboratory techniques quickly becomes prohibitively expensive and laborious when more than four orders of magnitude in length scales need to be resolved. This issue is particularly challenging in very fine-grained rocks such as mylonites and shales.Here, we investigate calcite-vein-bearing shales to illustrate how synchrotron X-ray fluorescence microscopy, ptychography, and small- and wide-angle transmission scattering can be used for the quantitative multi-scale analysis of micro- and nano-textures in rock. These analytical techniques are applied to thin sections or thin rock slabs on the centimetre-scale and provide information on length scales from hundreds of micrometres down to angstroms. Therefore, the considered array of synchrotron techniques covers up to eight orders of magnitude in length scale in terms of chemical and structural information. In our case study, we demonstrate how this suite of analytical techniques can be employed to reveal, for example, the relative timing of mineralisation events, trace-element chemistry, texture, and the structural width of fluid pathways such as grain boundaries
Molar concentration from sequential 2-D water-window X-ray ptychography and X-ray fluorescence in hydrated cells
Recent developments in biological X-ray microscopy have allowed structural information and elemental distribution to be simultaneously obtained by combining X-ray ptychography and X-ray fluorescence microscopy. Experimentally, these methods can be performed simultaneously; however, the optimal conditions for each measurement may not be compatible. Here, we combine two distinct measurements of ultrastructure and elemental distribution, with each measurement performed under optimised conditions. By combining optimised ptychography and fluorescence information we are able to determine molar concentrations from two-dimensional images, allowing an investigation into the interactions between the environment sensing filopodia in fibroblasts and extracellular calcium. Furthermore, the biological ptychography results we present illustrate a point of maturity where the technique can be applied to solve significant problems in structural biology
ToF-SIMS investigation of epoxy resin curing reaction at different resin to hardener ratios
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and principal components analysis (PCA) were used to analyze diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) epoxy resin blend cured with isophorone diamine (IPD) hardener at different resin to hardener ratios. The aim was to establish correlations between the hardener concentration and the nature and progress of the crosslinking reaction. Insights into the cured resin structure revealed using ToF-SIMS are discussed. Three sets of significant secondary ions have been identified by PCA. Secondary ions such as C14H7O+, CHO+, CH3O+, and C21H24O4+ showed variance related to the completion of the curing reaction. Relative intensities of CxHyNz+ ions in the cured resin samples are indicative of the un-reacted and partially reacted hardener molecules, and are found to be proportional to the resin to hardener mixing ratio. The relative ion intensities of the aliphatic hydrocarbon ions are shown to relate to the cured resin crosslinking density
The Ag M5N45N45 Auger photoelectron coincidence spectra of disordered Ag0.5Pd0.5 alloy
9 page(s
Multi-modal nanoscale imaging of materials and biology (Conference Abstract)
A central challenge for imaging complex systems, such as metal defect structures or whole animals, is that information about features spanning multiple length scales is required. Furthermore, a complete understanding of the underlying properties can often only be achieved by correlating information from multiple techniques. Here we present a number of recent developments combining coherent diffractive imaging (CDI) at X-ray wavelengths with complimentary imaging and spectroscopy methods in transmission and Bragg geometry for rapid and high throughput imaging that provides multi-variable, 3D information about complex systems..
Soft X-ray ptychography as a tool for in operando morphochemical studies of electrodeposition processes with nanometric lateral resolution
Highlights • Pulse-plating of Mn-oxide/polypyrrole nanocomposite studied in situ by ptychography. • Electrocrystallization followed in operando by dynamic coherent diffractive imaging. • Morphology and chemical state evolutions monitored in situ during electrodeposition. • Spectroscopic ptychography reveals valence distribution with nanometric resolution. • Local magnitude and phase spectra extracted from recostructued ptychographic images. Abstract Crucial for the advancement of electrochemical materials science is understanding the lateral variations in the elemental and chemical state of constituents induced by electrochemical reactions at nanoscales. This requires in situ studies to provide observables that contribute to both modeling beyond the phenomenological level and transducing exactly the functionally relevant quantities A range of X-ray coherent diffraction imaging (CDI) approaches has recently been proposed for imaging beyond the diffraction limit with potentially dramatic improvements of time resolution with chemical sensitivity. In this paper we report a selection of ptychography results obtained in situ after successive steps of electrochemically driven growth, complemented with absorption and phase spectroscopy at high lateral resolution. We demonstrate the onset of morphological instability feature formation and correlate the chemical state of Mn with local growth rate controlled by the current density distribution resulting from morphological evolution